Abstract: A communication method between a plurality of terminals and a resource allocation method in an infrastructure network are disclosed. A terminal according to an embodiment communicates with at least one other terminal using a particular frequency band in a third time section distinguished from a first time section for reception of a downlink data and a second time section for transmission of an uplink data, thereby providing a technology of generating a small-scale network partly with respect to a particular region in a network with an extensive coverage of an infrastructure network.

Abstract: Provided is a hidden node detection method and apparatus in a wireless communication system, the apparatus including a sensing unit to sense a first communication device transmitting a data signal from among a plurality of communication devices sharing a wireless channel, a transmitter to generate a reception notification signal in response to the sensing, and transmit the reception notification signal to the a plurality of communication devices through a band identical to a transmission band of the data signal, and a controller to prevent a collision with the data signal transmitted from the first communication device through the wireless channel by delaying processing of a data transmission request when the data transmission request is input from a second communication device among the plurality of communication devices while maintaining the transmitting of the reception notification signal.

Abstract: Disclosed is a method for managing network resources of a wireless terminal in a heterogeneous network environment and the method for managing network resources includes: searching for one or more networks which are accessible in the heterogeneous network environment; acquiring cycle information of the networks searched through the network searching; determining coexistence management cycles of the searched networks based on the cycle information; allocating one or more networks to be used in data transmission among the networks searched according to the coexistence management cycle and determining transmission management cycles of one or more allocated networks; and managing a resource of the searched network according to the coexistence management cycle and the transmission management cycle.

Abstract: Provided is a hidden node detection method and apparatus in a wireless communication system, the apparatus including a sensing unit to sense a first communication device transmitting a data signal from among a plurality of communication devices sharing a wireless channel, a transmitter to generate a reception notification signal in response to the sensing, and transmit the reception notification signal to the a plurality of communication devices through a band identical to a transmission band of the data signal, and a controller to prevent a collision with the data signal transmitted from the first communication device through the wireless channel by delaying processing of a data transmission request when the data transmission request is input from a second communication device among the plurality of communication devices while maintaining the transmitting of the reception notification signal.

Abstract: A communication method between a plurality of terminals and a resource allocation method in an infrastructure network are disclosed. A terminal according to an embodiment communicates with at least one other terminal using a particular frequency band in a third time section distinguished from a first time section for reception of a downlink data and a second time section for transmission of an uplink data, thereby providing a technology of generating a small-scale network partly with respect to a particular region in a network with an extensive coverage of an infrastructure network.

Abstract: To perform communication in a cognitive radio network, a cognitive radio apparatus according to an exemplary embodiment includes: an estimation module configured to generate a channel estimation signal to be transmitted to a predetermined reception apparatus positioned in a predetermined channel in the case of selecting the predetermined channel from among multiple channels; a communication module configured to transmit the channel estimation signal to the predetermined reception apparatus, and to receive a channel response signal from the predetermined reception apparatus; and a control module configured to control the communication module so that at least one of a communication signal set with respect to the predetermined channel and a variable communication signal obtained by varying the communication signal is transmitted to the predetermined reception apparatus, when it is determined that the predetermined channel is positioned in a deep fading section based on the channel response signal.

Abstract: The present invention provides a channel information providing method, a channel information providing database server, and a channel information providing system which receive channel quality information from a cognitive radio terminal which receives channel information based on position information and efficiently use channels using the received information. A channel information providing method which uses a database server to provide channel information to a cognitive radio terminal based on position information includes providing channel information to at least one cognitive radio terminal; receiving collected information regarding a quality of the channel from the at least one cognitive radio terminal; and determining to update the channel information provided in the providing using the information received in the receiving.

Abstract: Provided is a communication method of a secondary transmitter included in a multiple-antenna based multiple input multiple output (MIMO) cognitive radio communication system, the method including: estimating an interference channel between the secondary transmitter and a primary user in each of at least one first spectrum band that is being used in a primary system; calculating an orthogonal projection matrix to cancel interference with respect to the primary user from the interference channel; calculating an effective channel between the secondary transmitter and a secondary receiver based on the to orthogonal projection matrix; and selecting an index of an optimal spectrum band from the at least one first spectrum band based on the orthogonal projection matrix and the effective channel.

Abstract: The present invention relates to a method and apparatus for managing a backup channel in a multi-channel environment. According to an aspect of the present invention, the method of managing a backup channel in a multi-channel environment includes transmitting a control region of a super frame through a first channel constituting the multi-channel and transmitting a data region of the super frame to a destination terminal through a second channel constituting the multi-channel. A transmission quality of the first channel is acquired using the control region transmitted through the first channel.

Abstract: A method and apparatus for detecting a heterogeneous communication system is provided. The apparatus include a radio frequency (RF) signal reception unit configured to receive a signal from a particular communication system, a silent duration evaluation unit configured to evaluate a silent duration between frames on the basis of the received signal, and a system type decision making unit configured to determine the type of the particular communication system on the basis of the evaluated silent duration.

Abstract: Provided is a communication method of a secondary transmitter included in a multiple-antenna based multiple input multiple output (MIMO) cognitive radio communication system, the method including: estimating an interference channel between the secondary transmitter and a primary user in each of at least one first spectrum band that is being used in a primary system; calculating an orthogonal projection matrix to cancel interference with respect to the primary user from the interference channel; calculating an effective channel between the secondary transmitter and a secondary receiver based on the to orthogonal projection matrix; and selecting an index of an optimal spectrum band from the at least one first spectrum band based on the orthogonal projection matrix and the effective channel.

Abstract: A method of allocating channels to jobs requiring a channel allocation is provided using a sequential channel allocation method, a batch channel allocation method, or a channel allocation method including the sequential channel allocation method and the batch channel allocation method in a multi-channel cognitive radio network. As a result, it is possible to rapidly and optimally allocate channels to jobs requiring the channel allocation in the multi-channel CR network and to efficiently manage the network by minimizing the number of operational channels.

Abstract: The present invention relates to a method and apparatus for managing a backup channel in a multi-channel environment. According to an aspect of the present invention, the method of managing a backup channel in a multi-channel environment includes transmitting a control region of a super frame through a first channel constituting the multi-channel and transmitting a data region of the super frame to a destination terminal through a second channel constituting the multi-channel. A transmission quality of the first channel is acquired using the control region transmitted through the first channel.

Abstract: A method and apparatus for detecting a heterogeneous communication system is provided. The apparatus include a radio frequency (RF) signal reception unit configured to receive a signal from a particular communication system, a silent duration evaluation unit configured to evaluate a silent duration between frames on the basis of the received signal, and a system type decision making unit configured to determine the type of the particular communication system on the basis of the evaluated silent duration.

Abstract: A method and an apparatus for transmitting a packet in a communication system are provided. The method for transmitting a packet in a communication system includes receiving a compression packet use request message from a receiver; generating a specific preamble and transmitting the compression packet to a receiver; wherein the compression packet is generated by omitting information on overlapping frame header among a frame to be transmitted and attaching the specific preamble including the information on the omitted frame header.